Compilare: main.cpp: In function 'int main()': main.cpp:20:30: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("darb.in","r",stdin); ^ main.cpp:21:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("darb.out","w",stdout); ^ main.cpp:22:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:24:82: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &nr1, &nr2),arbore[nr1].push_back(nr2),arbore[nr2].push_back(nr1); ^